Aaron, I commend you for trying to find a form of exercise that will help not harm you. I have some issues with my back, hips and neck (not surgical) that I must address when undertaking any form of exercise. I'd like to reccomend Meghan Campbell of CAE Yoga. Her studio is located on Brown & Recker Roads in Mesa. Check out her website CAEyoga.com for contact information. She will conduct an initial session where she does a complete evaluation for any injurys, etc., before you undertake a class. She can work with you one-on-one, as well as, in a group. She is extremely knowledgable about injurys and specializes in rehabilitative yoga. I have been going to her for over a year, and she has helped me so much. If you speak to her, please mention my name, so she know how you heard of her.
Best wishes!
S.